Antibiotic complex

ABSTRACT

A novel aminoglycoside antibiotic complex designated herein as Bu-2183 is produced by fermentation of Pseudomonas sp. strain D946-B83, A.T.C.C. 31086. Complex Bu-2183 is known to consist of at least five components, said components being herein designated Bu-2183 A, A2, B, C and D. The complex and the individual aminoglycoside components Bu-2183 A, A2, and B are found to have a broad spectrum of antibacterial activity and are especially useful in inhibiting aminoglycoside-resistant organisms including Pseudomonas species.

CROSS-REFERENCE TO RELATED APPLICATION

This application is a divisional of co-pending U.S. application Ser. No. 627,391 filed Oct. 30, 1975, now U.S. Pat. No. 4,012,576, issued Mar. 15, 1977, which in turn is a continuation-in-part of U.S. application Ser. No. 532,137 filed Dec. 12, 1974 and now abandoned.

BACKGROUND OF THE INVENTION

(1) Field of the Invention

This invention relates to new aminoglycoside antibiotic complex and to its production, recovery and separation into five components, three of which are bioactive.

(2) Description of the Prior Art

Various antibiotics are known in the art including several aminoglycoside antibiotics such as kanamycin, gentamycin, streptomycin, neomycin, tobramycin and paromomycin. There exists a need, however, for additional new broad-spectrum antibiotics, particularly those having activity against aminoglycoside-resistant organisms such as Pseudomonas.

SUMMARY OF THE INVENTION

There is provided by the present invention a new aminoglycoside antibiotic complex designated Bu-2183, said complex being prepared by cultivating a new species of Pseudomonas designated Pseudomonas sp. strain D946-B83, A.T.C.C. No. 31086, in an aqueous nutrient medium containing assimilable sources of nitrogen and carbon under submerged aerobic conditions until a substantial amount of Bu-2183 complex is produced by said organism in said culture medium and optionally recovering the Bu-2183 complex from the culture medium. The invention also provides a process for producing as separate substances the individual components of the Bu-2183 complex including especially the antibiotic components designated Bu-2183 A, A₂ and B and the useful intermediate designated Bu-2183D, which process comprises producing the Bu-2183 complex by the above-described method, separating the antibiotic complex from the mycelium of the culture medium, adsorbing the Bu-2183 complex on a cationic ion-exchange resin, fractionally eluting the Bu-2183 components from the adsorbent and recovering the fractions of the desired components.

DESCRIPTION OF THE DRAWINGS

FIG. 1 shows the infra-red absorption spectrum of Bu-2183 A free base when pelleted in potassium bromide.

FIG. 2 shows the proton magnetic resonance spectrum of Bu-2183 A as the hydrochloride salt dissolved in D₂ O using 2,2-dimethyl-2-silapentane-5-sulfonate as the internal standard as determined with a JEOL 60 MHz NMR spectrometer (type TNM-C-60HL).

FIG. 3 shows the infra-red absorption spectrum of Bu-2183 A₂ free base when pelleted in potassium bromide.

FIG. 4 shows the proton magnetic resonance spectrum of Bu-2183 A₂ as the hydrochloride salt dissolved in D₂ O using 2,2-dimethyl-2-silapentane-5-sulfonate as the internal standard as determined with a JEOL 60 MHz spectrometer (type TNM-C-60HL).

FIG. 5 shows the infra-red absorption spectrum of Bu-2183 B free base when pelleted in potassium bromide.

FIG. 6 shows the proton magnetic resonance spectrum of Bu-2183 B as the hydrochloride salt dissolved in D₂ O using 2,2-dimethyl-2-silapentane-5-sulfonate as the internal standard as determined with a JEOL 60 MHz NMR spectrometer (type TNM-C-60HL).

FIG. 7 shows the infra-red absorption spectrum of Bu-2183 D free base when pelleted in potassium bromide.

FIG. 8 shows the proton magnetic resonance spectrum of Bu-2183 D as the hydrochloride salt dissolved in D₂ O using 2,2-dimethyl-2-silapentane-5-sulfonate as the internal standard as determined with a JEOL 60 MHz NMR spectrometer (type TNM-C-60HL).

DETAILED DESCRIPTION

This invention relates to a novel aminoglycoside antibiotic complex designated herein as Bu-2183 and to its preparation by fermentation of a new species of Pseudomonas designated Pseudomonas sp. strain D946-B83 in the Bristol-Banyu culture collection. The above organism is a psychrophilic soil bacterium which was isolated from an Indian soil sample. A culture of the organism has been deposited in the American Type Culture Collection, Washington, D.C., and added to its permanent collection of microorganisms as A.T.C.C. 31086.

The novel aminoglycoside complex of this invention comprises at least five aminoglycoside components, three of which designated Bu-2183 A, A₂, and B are found to be bio-active and two, designated Bu-2183 C and D, are bio-inactive.

The antibiotic complex Bu-2183 and each of the three above-mentioned bio-active antibiotic components have a broad spectrum of antibacterial activity and inhibit most of the aminoglycoside-resistant organisms including Pseudomonas species. The antibiotics Bu-2183, Bu-2183A, Bu-2183A₂ and Bu-2183B are valuable as antibacterial agents, as nutritional supplements in animal feeds and as therapeutic agents in poultry and animals, including man. They are valuable in the treatment of infectious diseases caused by Gram-positive and Gram-negative bacteria, particularly diseases caused by aminoglycoside-resistant organism. One of the novel bio-inactive components of the fermentation-produced complex, i.e. Bu-2183 D, is of use as an intermediate in the semi-synthetic preparation (as by N-acylation) of the bio-active components Bu-2183 A, A₂ and B.

The Microorganism

The Bu-2183 antibiotic producing organism designated Pseudomonas sp. strain D946-B83, A.T.C.C. 31086 is a strictly aerobic, non-sporulating and Gram-negative bacterium. The cells are rod-shaped and produce unipolar multiflagella. Strain D946-B83 is a psychrotrophic organism growing at 4° C. but not at 41° C. It produces fluorescent pigment in glutamate medium and skimmed milk solution but not in King's B medium (H. Iizuka, & K. Komagata: An Attempt At Grouping Of The Genus Pseudomonas. J. Gen. Appl. Microbiol. 9: 73-82, 1963). Cytochrome oxidases are not produced. The morphological, cultural and physiological characteristics of strain D946-B83 are described below:

Morphology

Strain D946-B83 is characterized by having motile, non-sporulating and Gram-negative rods. The cells are straight, occasionally bent along the long axis, and produce uni-polar tuft flagella. Poly-β-hydroxy butyrate is not contained as a cellular reserve (R. Y. Stanier, N. J. Palleroni & M. Doudoroff: The Aerobic Pseudomonads: A Taxonomic Study. J. Gen Microbiol. 43: 159-271, 1966). No sheath, stalk or slime is produced.

Growth Characteristics

Colony on nutrient agar and yeaat extract agar: Abundant growth. 0.5-1.5 mm diameter after 1 day. Diffused, circular and somewhat raised. Smooth and soft. Opaque, whitish cream, later light buff-orange. Slightly viscous. No diffusible pigment.

Nutrient broth and yeast extract broth: Abundant growth. Turbid, later with sediment and occasionally pellicle.

Yeast extract agar stab: Growth only on surface. No growth under any anaerobic condition.

Chemically defined inorganic salts medium: Moderate growth when added with glucose or lactate as a sole carbon source.

Requirement for growth factor: None.

Growth temperature: Restricted growth at 4° C. Moderate to abundant growth at 10°-32° C. Scant growth at 37° C. No growth at 41° C.

Effect of media pH: No growth at pH 4.0. Restricted growth at pH 4.5 and pH 10.5-11.0. Moderate to good growth at pH 5.5-9.5.

NaCl effect: No growth at 12% NaCl. Restricted growth at 6-9%. Moderate growth at 5% or less.

The above-described morphological and cultural characteristics are similar to those of the family Pseudomonadaceae.

Physiological Characteristics

Strain D946-B83 produces diffusible fluorescent pigment in certain media but not in others while a known species of Pseudomonas, i.e. Pseudomonas fluorescens, shows abundant fluorescence production (Table 1).

The physiological and biochemical characteristics of strain D946-B83 are shown in Table 2. Utilization of carbohydrate and other carbon sources by the organism is shown in Table 3 comparatively with those of two known Pseudomonal species, i.e. Ps. fluorescens and Ps. aeruginosa.

Taxonomy

Strain D946-B83 appears to belong to the pseudomonads group in view of the above-described morphological, cultural and physiological characteristics. According to the taxonomic system proposed by Stanier et al. (R. Y. Stanier, N. J. Palleroni and M. Doudoroff: The Aerobic Pseudomonads: A Taxonomic Study. J. Gen. Microbiol. 43: 159-271, 1966) for the aerobic pseudomonads, strain D946-B83 is rather closely related to Pseudomonas fluorescens except for its negative egg-yolk reaction, negative utilization of inositol and negative oxidase production. Among the 13 type species of aerobic pseudomonads examined by Stanier, only Pseudomonas maltophilia is reported to show negative oxidase reaction. This organism, however, is quite different from strain D946-B83 in the lack of fluorescent pigment, positive methionine requirement, absence of growth at 4° C., negative arginine dihydrolase and different substrate utilization. Thus, strain D946-B83 is considered to belong to a new species of the genus Pseudomonas.

Preparation of the Antibiotics

Antibiotic complex Bu-2183 is produced by cultivating the novel Pseudomonas species designated Pseudomonas sp. strain D946-B83, A.T.C.C. 31086, under submerged aerobic conditions in an aqueous nutrient medium. The organism is grown in a nutrient medium containing an assimilable carbon source, for example an assimilable carbohydrate. Examples of preferred carbon sources include glucose, fructose, mannose, glycerol and the like. The nutrient medium should also contain an assimilable nitrogen source such as, for example, fish meal, soybean meal, peptones, etc. Nutrient inorganic salts may also be incorporated in the culture medium, and such salts may comprise any of the usual salts capable of providing sodium, potassium, ammonium, calcium, phosphate, sulfate, chloride, bromide, nitrate, carbonate or like ions.

Production of the Bu-2183 complex can be effected at any temperature conducive to satisfactory growth of the organism, e.g. 10°-32° C., and is most preferably carried out at a temperature of around 28°-30° C. Ordinarily optimum production is obtained in 3-5 days. The optimum pH range of the medium is found to be about pH 5.5-9.5 and, most advantageously, the medium is adjusted to a pH of about 7. When tank fermentation is to be carried out, it is desirable to produce a vegetative inoculum in a nutrient broth by inoculating the broth culture with a slant or soil culture or a lyophilized culture of the organism. After obtaining an active inoculum in this manner, it is transferred aseptically to the fermentation tank medium.

A preferred procedure for preparing the Bu-2183 antibiotic complex is as follows:

A well-grown agar slant of Pseudomonas strain D946-B83 was used to inoculate seed medium containing 3% glucose, 2% fish meal, 0.5% soybean meal, 0.2% peptone and 0.6% CaCO₃, the pH being adjusted to 7.0 before sterilization. The seed culture was incubated at 28° C. for 48 hours on a rotary shaker (250 rpm), and 2 ml. of the growth was transferred to 100 ml. of the fermentation medium in a 500 ml. Erlenmeyer flask which contained 2% glycerol, 2% linseed meal, 1% peanut meal, 2% fish meal, 0.3% (NH₄)₂ SO₄ and 0.5% CaCO₃. Antibiotic production reached a maximum after 3 to 5 days shaking at 28° C. The antibiotic activity in the fermentation broth was determined by a paper disc-agar diffusion assay using Bacillus subtilis PCI 219 as the test organism. Strain D946-B83 produced 1,500 to 2,000 mcg./ml. of the antibiotic complex by the shake flask fermentation method.

After optimum broth potency has been obtained (as determined for example by the assay procedure mentioned above), the broth is adjusted to a pH of about 2 whereby the basic water-soluble antibiotic complex is separated from the mycelium and dissolved in the aqueous fermentation medium. The broth is then filtered, preferably with filter aid, and the filtrate containing the antibiotic neutralized to a pH of about 7. The neutralized filtrate is passed through a cationic ion-exchange resin, preferably of the IRC-50 Amberlite type in the ammonium form. The resin is then washed with water and dilute (N/50) NH₄ OH and the antibiotic complex eluted from the resin with a suitable eluant, e.g. N/2 NH₄ OH. The active eluants are combined, concentrated in vacuo and evaporated or lyophilized to obtain the crude Bu-2183 antibiotic complex.

The crude solid thus obtained was shown by TLC to contain at least three active components which have been designated herein as Bu-2183 A, A₂ and B as well as at least two inactive components which have been designated herein as Bu-2183 C and D. The Bu-2183 complex may be separated into its components Bu-2183 A, A₂, B, C and D by use of a cationic ion-exchange resin, preferably a resin of the Amberlite CG-50 type in the ammonium form. The complex after being dissolved in water is applied to the resin, washed with water and dilute (N/40) ammonium hydroxide and eluted with a suitable eluant. Ammonium hydroxide (N/20) has been found to allow separation of components Bu-2183 A and B. Further elution of the column with a more concentrated ammonium hydroxide solution, e.g. (N/10), gives Bu-2183 C and D which are ninhydrin-positive but bioinactive. To obtain purified component Bu-2183 A₂, it is usually necessary to perform additional column chromatography on the Bu-2183 A fraction to separate the components Bu-2183 A₂ and Bu-2183 A. Complete separation and purification of each component is achieved by repeating the chromatographic separation procedure described above. As shown below in Table 4, two TLC systems designated herein as S-117 and S-122 were found to be suitable to differentiate the four components Bu-2183 A, B, C and D. During the chromatographic purification of component Bu-2183 A as described in detail in the examples which follow, a further bio-active aminoglycoside component was found which is designated herein as Bu- 2183 A₂. Component Bu-2183 A₂ may be differentiated from component Bu-2183 A by the TLC systems S-117 and S-122 as shown below in Table 5.

Characterization Data for Bu-2183 Antibiotic Components

Bu-2183 A

The antibiotic substance Bu-2183 A is a white amorphous base which is soluble in water, slightly soluble in methanol and ethanol and practically insoluble in n-butanol, acetone and other common organic solvents.

Antibiotic Bu-2183 A is capable of forming salts with acids, and pharmaceutically acceptable acid addition salts of the antibiotic are included within the present invention. Examples of suitable pharmaceutically acceptable acid addition salts include the non-toxic salts with organic and inorganic acids such as for example hydrochloric, sulfuric, phosphoric, acetic, stearic, propionic, tartaric, maleic, benzoic, succinic and the like.

Component Bu-2183 A gives positive reactions with ninhydrin and anthrone reagents but negative reactions with Tollens, Fehling and Sakaguchi reagents.

The specific rotation of Bu-2183 A base is [α]_(D) ²¹ = + 78.5° (c, 1.0, water).

A sample of component Bu-2183 A when precipitated from ethanol analyzed as C₁₅ H₃₁ N₃ O₉.C₂ H₅ OH.H₂ O.

Anal. Calc'd.: C, 44.24; H, 8.52; N, 9.11; O, 38.13. Found: C, 44.25; H, 8.08; N, 9.11; 0(by difference), 38.56.

The di-N-acetate of Bu-2183 A was obtained as colorless needles, m.p. 149°-150° C. It has a molecular weight of 481 as determined by osmometry and analyzed as C₁₉ H₃₅ N₃ O₁₁.H₂ O.

Anal. Calc'd.: C, 45.68; H, 7.47; N, 8.41; O, 38.44. Found: C, 45.73; H, 7.49; N, 8.19; O(by difference), 38.59.

Bu-2183 A is weakly basic and has titratable groups having pK_(a) ' values of 6.90 and 9.40 in water. The approximate molecular weight of the antibiotic as calculated from titration data is 398.

Component Bu-2183 A exhibits only end absorption of ultraviolet light. When pelleted in potassium bromide, it has an infrared spectrum substantially as shown in FIG. 1 with characteristic absorption bands at the following wave numbers in cm⁻¹ : 1635 and 1570 (amide) and 1080 and 1020 (hydroxyl groups). When dissolved in deuterium oxide at a concentration of about 8%, the NMR spectrum of Bu-2183 A hydrochloride salt is substantially as shown in FIG. 2. The spectrum shows an anomeric proton at δ5.17 ppm (1H, d, J = 3 Hz) and a propionyl group at δ1.12 (3H, t, J = 7.5 Hz) and 2.29 (2H, q, J = 7.5 Hz) ppm.

The structure of Bu-2183 A has been determined to be ##STR1## Bu-2183 A₂

Antibiotic component Bu-2183 A₂ like Bu-2183 A above is a white amorphous base which is soluble in water, slightly soluble in methanol and ethanol and practically insoluble in n-butanol, acetone and other common organic solvents. It is capable of forming salts with acids, and pharmaceutically acceptable acid addition salts of the Bu-2183 base are included within the present invention. Component Bu-2183 A₂ gives positive ninhydrin and anthrone reactions and negative Tollens, Fehling and Sakaguchi reactions.

The specific rotation of Bu-2183 A₂ base is [α]_(D) ²⁵ = + 79.1°(c, 0.43, H₂ O).

A sample of Bu-2183 A₂ isolated on the carbonate salt analyzed as C₁₆ H₃₃ N₃ O₉.1/2 H₂ CO₃.

Anal. Calc'd.: C, 44.79; H, 7.75; N, 9.50; O, 37.96. Found: C, 44.35; H, 7.83; N, 9.21; O(by difference), 38.61.

Component Bu-2183 A₂ exhibits only end absorption of ultraviolet light. When pelleted in KBr, it has an infrared spectrum substantially as shown in FIG. 3. When dissolved in D₂ O at a concentration of about 6%, the NMR spectrum of Bu-2183 A₂ hydrochloride salt is substantially as shown in FIG. 4. Component Bu-2183 A₂ may be distinguished from Bu-2183 A and Bu-2183 B by the presence of an n-butyryl group in the NMR spectrum at δ0.92 (3H, t), 1.63 (2H, sixtet) and 2.30 (2H, t) ppm in place of the propionyl or acetyl group in components A & B.

The structure of component Bu-2183 A₂ has been determined to be ##STR2## Bu-2183 B

The antibiotic Bu-2183 B is very similar in appearance and solubility to components Bu-2183 A and A₂, being a white amorphous base which is soluble in water, slightly soluble in methanol and ethanol and practically insoluble in n-butanol, acetone and other common organic solvents.

Antibiotic Bu-2183 B is capable of forming salts with acids, and pharmaceutically acceptable acid addition salts of the antibiotic are included within the present invention.

Component Bu-2183 B gives positive reactions with ninhydrin and anthrone reagents but negative reactions with Tollens, Fehling and Sakaguchi reagents.

The specific rotation of Bu-2183 B base is [α]_(D) ²¹ = + 85° (c, 1.0, water).

A sample of component Bu-2183 B when precipitated from ethanol analyzed as C₁₄ H₂₉ N₃ O₉.C₂ H₅ OH.H₂ O.

Anal. Calc'd.: C, 42.95; H, 8.34; N, 9.36; O, 39.35. Found: C, 42.69; H, 7.78; N, 8.86; O(by difference), 40.67.

The di-N-acetate of Bu-2183 B was obtained as colorless prisms, m.p. 159°-162° C. It has a molecular weight of 484 as determined by osmometry and analyzed as C₁₈ H₃₃ N₃ O₁₁.H₂ O.

Anal. Calc'd: C, 44.53; H, 7.27; N, 8.66; O, 39.54. Found: C, 44.96; H, 7.44; N, 8.52; O(by difference), 39.08.

Bu-2183 B is weakly basic and has titratable groups having pK_(a) ' values of 7.15 and 9.35 in water. The approximate molecular weight of the antibiotic as calculated from titration data is 409.

Component Bu-2183 B exhibits only end absorption of ultraviolet light. When pelleted in potassium bromide, it has an infrared spectrum substantially as shown in FIG. 5 with characteristic absorption bands at the following wave numbers in cm⁻¹ : 1635 and 1570 (amide) and 1080 and 1020 (hydroxyl groups). When dissolved in deuterium oxide at a concentration of 10%, the NMR spectrum of Bu-2183 B hydrochloride salt is substantially as shown in FIG. 6. The NMR spectrum shows that Bu-2183 B may be distinguished from Bu-2183 A and A₂ by the presence of an acetyl group at δ2.02 ppm (3H, s,) instead of the propionyl or n-butyryl group as in A and A₂, respectively.

Component Bu-2183 B has the structure ##STR3##

Characterization Data For Intermediate Bu-2183 D

The bio-inactive component Bu-2183 D is a white amorphous base which is soluble in water, slightly soluble in methanol and ethanol, and practically insoluble in n-butanol, acetone and other common organic solvents.

Compound Bu-2183 D is capable of forming salts with acids and such acid addition salts of the base are included within the present invention.

Component Bu-2183 D gives positive reactions with ninhydrin and anthrone reagents but negative reactions with Tollens, Fehling and Sakaguchi reagents.

The specific rotation of Bu-2183 D base is [α]_(D) ²¹ = + 72.5° (c, 1.0, water).

A sample of component Bu-2183 D isolated as the carbonate salt analyzed as C₁₂ H₂₇ N₃ O₈. H₂ CO₃.

Anal. Calc'd.: C, 38.70; H, 7.25; N, 10.42; O, 43.63. Found: C, 38.86; H, 6.93; N, 10.14; O (by difference), 44.07.

Bu-2183 D is weakly basic and has three titratable groups with pKα' values of 6.95 (2 equivalents) and 9.68 in water.

The tri-N-acetate of Bu-2183 D was obtained as colorless prisms, m.p. 159°-162° C. This salt was determined to be identical with the di-N-acetate of Bu-2183 B.

Component Bu-2183 D exhibits only end absorption of ultraviolet light. When pelleted in potassium bromide, it has an infrared spectrum substantially as shown in FIG. 7. The spectrum indicates the lack of the amide carbonyl bands which are present in the bioactive components Bu-2183 A, A₂ and B. When dissolved in deuterium oxide at a concentration of 10%, the NMR spectrum of Bu-2183 D hydrochloride salt is substantially as shown in FIG. 8. The structure of Bu-2183 D has been determined to be ##STR4##

Structure Determination of Bu-2183 Components

Mild acidic hydrolysis of Bu-2183 A and B (1N HCl/MeOH, 80° C., 3 hours) gave the same desacyl compound, C₁₂ H₂₇ N₃ O₈, which was identical with component Bu-2183 D obtained by chromatographic separation of the crude Bu-2183 complex. Total N-acetylation of Bu-2183 D gave tri-N-acetate, C₁₈ H₃₃ N₃ O₁₁, which was identified as the di-N-acetate of component Bu-2183 B.

Acid hydrolysis of Bu-2183 B in methanolic hydrogen chloride (saturated, refluxing temperature, 24 hours) yielded an aglycone and an amino sugar along with component Bu-2183 D. The aglycone was isolated as the crystalline sulfate, mp 263°-264° C, which analyzed for C₆ H₁₆ N₂ O₄.H₂ SO₄.

Anal. Calc'd.: C, 25.90; H, 6.52; N, 10.07; S, 11.52. Found: C, 26.10, H, 6.47, N, 9.93, S, 11.29.

The 220 MH_(z) NMR spectrum of its N,O-hexaacetate along with mass spectral data obtained with the N-acetyl-O-TMS, N-acetyl-diisopropylidene and hexa-N,O-acetyl derivatives of the aglycone suggested a 1,4-diamino-2, 3, 5, 6-tetra-ol structure for the aglycone part.

The di-N-acetate of the aglycone was obtained as colorless needles, mp 114°-115° C., and analyzed for C₁₀ H₂₀ N₂ O₆.

Anal. Calc'd.: C, 45.45; H, 7.63; N, 10.60. Found: C, 45.37; H, 7.97; N, 10.57.

Since the D-glucose-type configuration was thought to be most probable for the aglycone, the preparation of 1, 4-diamino-1, 4-dideoxy-D-sorbitol from 4-amino-4-deoxy-D-glucose was carried out and the product was shown to be the aglycone by TLC and NMR analysis.

The amino sugar part obtained after the above acidic methanolysis of component B was purified by Amberlite CG-50 chromatography and separated into α and β forms of methylglycoside, the α-form being the major product. N-Acetylation of the α-methylglycoside yielded colorless prisms, mp 185°-186° C. which analyzed for C₉ H₁₇ NO₆.

Anal. Calc'd: C, 45.95; H, 7.28; N, 5.95. Found: C, 45.93; H, 7.43; N, 5.88.

The mass spectrum of this N-acetyl derivative showed a peak at m/e 204 (M -31) attributable to the loss of a glycosidic methoxyl group from the molecule. Thus, the free amino sugar should have the formula of C₆ H₁₃ NO₅.

The α and β forms of methylglycoside were identified as methyl 4-amino-4-deoxy-α- and β-D-glucopyranoside, respectively, by the IR and NMR spectra of their tetra-N,O-acetyl derivatives. The IR spectra of authentic specimens of these sugars isolated from 4-trehalosamine (J. Antibiotics, 27, 145, 1974) were in agreement with the IR spectra of the experimental samples.

Acid hydrolysis of Bu-2183 D in 6N HCl (reflux, 3 hours) gave the same aglycone and amino sugar as those isolated from the hydrolyzate of Bu-2183 B.

Bu-2183 C obtained by chromatographic separation of the crude Bu-2183 complex was hydrolyzed in methanol containing 1N HCl at refluxing temperature for 3 hours. The aglycone part was identical with that of the other components of Bu-2183 and the sugar portion was identified as methyl D-glucoside by TLC, NMR and gas chromatography. Accordingly, the molecular formula for Bu-2183 C is C₁₂ H₂₆ N₂ O₉.

Based on the above data the structures of the Bu-2183 components were determined to be as follows:

    ______________________________________                                          ##STR5##                                                                      Bu-2183 Component   R                                                          ______________________________________                                         A                   C.sub.2 H.sub.5 CONH                                       B                   CH.sub.3 CONH                                               A.sub.2            n-C.sub.3 H.sub.7 CONH                                     C                   HO                                                         D                   NH.sub.2.                                                  ______________________________________                                    

Antimicrobial Activity

In vitro tests indicate that the complex Bu-2183 and the individual antibiotic components Bu-2183 A, A₂ and B have a broad spectrum of antibacterial activity. The antibiotic complex and active components are particularly useful in inhibiting most aminoglycoside-resistant organisms. Component Bu-2183 A₂ is found to be more active than Bu-2183 B but less active than Bu-2183 A.

The minimum inhibitory concentrations (MIC) of Bu-2183 A and B were determined against a wide variety of bacteria by the two-fold agar dilution method on Nutrient Agar plates. The inocula-replicating device of Steers et al. was used. Inoculum size was adjusted to be 10⁴ dilution of overnight culture of the test organisms in Heart Infusion Broth (Difco). The results are shown in Table 6 along with those of kanamycin which was comparatively tested as a reference antibiotic.

The intrinsic activities of Bu-2183 A and B are moderate or rather weak in terms of MIC values, the component A being about 2-4 fold more active than B. However, they exhibit a broad spectrum of antibacterial activity against Gram-positive and Gram-negative bacteria including many of the aminoglycoside-resistant organisms and Pseudomonas strains.

Table 7 below shows minimum inhibitory concentrations of components Bu-2183 A and A₂ against several pathogenic organisms.

A sample of Bu-2183 complex of approximately 30-40% purity was found to inhibit E. coli A20365 at a concentration of 12.5 mcg./ml., K. pneumoniae D-11 at a concentration of 12.5 mcg./ml., and Ps. aeruginosa A9930 at a concentration of 25 mcg./ml.

Effect Of Media pH On MIC

Effect of media pH on the MIC of Bu-2183 A was studied by two-fold agar dilution method using Nutrient Agar Medium at pH 6.0, 7.0, 8.0 and 9.0. The results shown in Table 8 indicated that the activity of Bu-2183 A increased at alkaline pH and decreased at acidic pH.

Effect Of Media

The effect of media on the activity of Bu-2183 A and B was determined against 8 test organisms. The media tested were Nutrient Agar, Heart Infusion Agar and Mueller-Hinton Agar. The media pH was adjusted at pH 8. As shown in Table 9, the greatest in vitro activity was demonstrated when Nutrient Agar was used as the test medium.

In Vivo Activity And Toxicity

Bu-2183 A and B were evaluated in vivo in experimental infections of mice. The pathogenic bacteria employed were S. aureus Smith, E. coli NIHJ and Ps. acruginosa A9930. Mice were challenged with a 100 × LD₅₀ dose of the pathogens in a 5% suspension of hog gastric mucin. A single subcutaneous treatment with the antibiotic was made immediately after the bacterial challenge (0 hour), and in a double dose schedule the antibiotic was administered at 0 and 3 hours after the challenge. Groups of 5 mice were used for each dosage level and the animals were observed for 5 days to determine the median protective dose (PD₅₀).

The results are shown in Table 10. Bu-2183 A and B afforded in vivo activity against all three of the infections tested.

The acute toxicity of Bu-2183 A and B was determined in mice by the subcutaneous and intravenous routes. The mice were observed for 15 days and the intravenous (i.v.) and subcutaneous (s.c.) LD₅₀ 's of component Bu-2183 A were found to be 2500 mg./kg. and 1000 mg./kg., respectively. Component Bu-2183 B was much less toxic than Bu-2183 A and no death occurred at doses up to 2000 mg./kg. by either i.v. or s.c. routes during the observation period of 15 days.

Utility Of Component Bu-2183 D

Component Bu-2183 D while bio-inactive is a valuable intermediate in the semi-synthetic preparation of the bio-active components Bu-2183 A, A₂ and B. Thus, the free amino group of intermediate Bu-2183 D (after suitable protection of other reactive functional groups) may be N-acylated according to methods known per se to produce (after removal of any protecting groups) the N-butyryl derivative Bu-2138A, the N-acetyl derivative Bu-2183B or the N-propionyl derivative Bu-2183A₂.

                  Table 1                                                          ______________________________________                                         Production Of Fluorescent Pigment                                                         Bu-2183 Producer                                                                             Ps. Fluorescens                                       Medium     D946 - B83    NIHJ B254                                             ______________________________________                                         Yeast extract agar                                                                        -             +                                                     King's B medium                                                                           -˜±  ++                                                    20% Skimmed milk                                                                          ++            ++                                                    solution                                                                       Glutamate broth                                                                           ++            ++                                                    ______________________________________                                    

                                      Table 2                                      __________________________________________________________________________     Physiological And Biological Characteristics Of Strain D946-B83                Test           Response  Method & Medium Employed                              __________________________________________________________________________     Arginine dihydrolase                                                                          Positive  Modified method of Stanier et al.sup.1)               Catalase       Positive  Hydrogen peroxide on the colony                       Oxidase        Negative  Tested by three different methods.sup.1,4)            (cytochrome oxidase)                                                           Extracellular hydrolases                                                       Gelatin hydrolase                                                                             Positive  Method of Stanier et al.sup.1)                        Starch hydrolase                                                                              Negative  Method of Stanier et al.sup.1)                        Voges-Proscauer reaction                                                                      Negative  Peptone broth plus 1% glucose                         Indole production                                                                             Negative  Peptone broth (Kovac's reagent)                       H.sub.2 S production from                                                                     Negative  Ammonium-inorganic salts plus cysteine                cysteine and thiosulfate and thiosulfate                                                                Lead acetate paper for detection of H.sub.2 S         Gelatin liquefaction                                                                          Positive  Peptone broth plus 25% gelatin.sup.5)                                (rapidly liquefied)                                             Reactions in skimmed milk                                                                     Greenish yellow                                                                          20% skimmed milk solution sterilized by               solution       fluorescent pigment                                                                      mild autoclaving (0.5 kg./cm.sup.2 for                               produced. 5 minutes)                                                           Peptonized.                                                                    pH alkalized                                                    Utilization of nitrate-N                                                                      Positive  Rhodes' inorganic salts-glycerol-nitrate                                       medium.sup.2)                                         Nitrite production from                                                                       Positive  Rhodes' inorganic salts-glycerol-nitrate              nitrate                  medium.sup.2)                                                        Negative  Peptone broth plus 0.1% KNO.sub.3                     Utilization of ammonium-N                                                                     Positive  Koser's citrate medium                                Ammonia production from                                                                       Positive  Peptone broth (Nessler's reagent)                     peptone                                                                        Denitrification                                                                               Negative  Method of Stanier et al.sup.1)                        Gas from carbohydrate                                                                         Negative  Nutrient broth plus 1% glucose                        Utilization of urea                                                                           Positive  Christensen's urea medium                             Utilization of citrate                                                                        Positive  Simmon's citrate medium and Koser's                                            citrate medium                                        Utilization of oxalate                                                                        Negative  Oxalate instead of citrate in Simmon's                                         and Koser's media                                     Egg-yolk reaction                                                                             Negative  Method employed by Stanier et al.sup.1)               Cleavage mechanism of                                                                         Ortho-cleavage                                                                           Modified method of Stanier et al.sup.1)               aromatic compound                                                              Production of phenazine pig-                                                                  Negative  King's A medium                                       ments including pyocyanin,                                                     chloraphine and phenazine                                                      α-carboxylic acid                                                        __________________________________________________________________________      .sup.1) R. Y. Stanier, N. J. Palleroni & M. Doudoroff: The Aerobic             Pseudomonads: A Taxonomic Study. J. Gen. Microbiol. 43: 159-271, 1966          .sup.2) M. E. Rhodes:The Characterization of Pseudomonas Fluorescens. J.       Gen. Microbiol. 21: 221-263, 1959                                              .sup.3) H. Iizuka & K. Komagata: An Attempt At Grouping Of The Genus           Pseudomonas, J. Gen Appl. Microbiol. 9: 73-82, 1963                            .sup.4) H. Iizuka & K. Komagata: Taxonomy Of Genus Pseudomonas With            Special Reference To Their Modes Of Metabolism Of Carbon Compounds. J.         Gen. Appl. Microbiol. 9: 83-95, 1963                                           .sup.5) V. B. D. Skerman: Abstracts Of Microbiological Methods.                Wiley-Interscience, New York, London, Sydney and Toronto, P. 364, 1969   

                  Table 3                                                          ______________________________________                                         Utilization Of Carbon Sources                                                                        Ps.       Ps.                                                        Strain    fluorescens                                                                              aeruginosa                                     Substrate   D946-B83  NIHJ B254 ATCC 19660                                     ______________________________________                                         Glycerol    +         +         +                                              L-Arabinose +         +         -                                              D-Xylose    +         +         -                                              L-Rhamnose  -         -         -                                              D-Fructose  +         +         +                                              D-Galactose +         +         -                                              D-Glucose   +         +         +                                              D-Mannose   +         +         -                                              D-Fucose    -         -         -                                              Trehalose   +         +         -                                              Cellobiose  -         -         -                                              Maltose     -         -         -                                              Sucrose     -         -         -                                              Lactose     -         -         -                                              Raffinose   -         -         -                                              Inositol    -         +         -                                              D-Mannitol  +         +         +                                              D-Sorbitol  -         +         -                                              Dulcitol    -         -         -                                              Geraniol    -         -         +                                              Starch      -         -         -                                              Cellulose   -         -         -                                                          -         -         -                                              Inulin      -         -         -                                              Salicin     -         -         -                                              Acetate     +         +         +                                              Propionate  +         +         +                                              β-OH-butyrate                                                                         +         +         +                                              2-Ketogluconate                                                                            +         +         +                                              Succinate   +         +         +                                              Maleate     -         -         -                                              Glycollate  -         -         -                                              DL-Lactate  +         +         +                                              Pelargonate +         +         +                                              Adipate     -         -         +                                              p-OH-benzoate                                                                              +         +         +                                              m-OH-benzoate                                                                              -         -         -                                              Methanol    -         -         +                                              Ethanol     -         -         +                                              n-Propanol  -         -         +                                              Phenol      -         -         -                                              Cresol      -         -         +                                              Monoethanolamine                                                                           -         -         -                                              Monoethylamine                                                                             -         -         -                                              Diethylamine                                                                               -         -         -                                              Triethylamine                                                                              -         -         -                                              Testosterone                                                                               -         -         -                                              Acetamide   -         -         +                                              Arginine    +         +         +                                              Valine      +         +         +                                              Norleucine  -         -         -                                              D-Tryptophan                                                                               -         -         -                                              δ-Aminovalerate                                                                      +         -         +                                              Betaine     +         +         +                                              Putrescine  +         +         +                                              ______________________________________                                          Basal medium contains per liter: 40 ml. of 1M-phosphate buffer (pH 6.8);       g., (NH.sub.4).sub.2 SO.sub.4 ; 20 ml. of Hutner's vitamin-free mineral        salts solution.                                                          

                                      Table 4                                      __________________________________________________________________________     TLC Of Bu-2183 Components                                                                                 Rf*                                                 System                                                                             Plate                                                                               Solvent System    A  B  C  D                                          __________________________________________________________________________     S-117                                                                              silica gel                                                                          CHCl.sub.3 --CH.sub.3 OH--28%NH.sub.4 OH                                                         0.39                                                                              0.30                                                                              0.21                                                                              0.23                                                (1:3:2)                                                               S-122                                                                              silica gel                                                                          CHCl.sub.3 --CH.sub.3 OH--2N NH.sub.4 OH--                                     CH.sub.3 COOH     0.38                                                                              0.27                                                                              0.15                                                                              0.03                                                (20:65:40:5)                                                          __________________________________________________________________________

                  Table 5                                                          ______________________________________                                         TLC Of Bu-2183 Components A & A.sub.2                                                                  Rf*                                                    System                                                                               Plate  Solvent System       A    A.sub.2                                 ______________________________________                                         S-117 silica CHCl.sub.3 --CH.sub.3 OH--28%NH.sub.4 OH                                                            0.49 0.57                                          gel    (1:3:2)                                                           S-122 silica CHCl.sub.3 --CH.sub.3 OH--2N NH.sub.4 OH--                              gel    CH.sub.3 COOH        0.39 0.48                                                 (20:65:40:5)                                                      ______________________________________                                           *detection: ninhydrin reagent                                           

                                      Table 6                                      __________________________________________________________________________     Antibacterial Spectra Of Bu-2183 A And B                                                           MIC (mcg/ml.)                                              Code #                                                                              Test Organism  Bu-2183 A                                                                            Bu-2183 B                                                                            Kanamycin A                                    __________________________________________________________________________     Sa-2 S. aureus Smith                                                                               12.5  50    0.2                                            Sa-3 S. aureus D193 25    25    0.4                                            Sa-4 S. aureus D133 25    >100  0.8                                            Sa-9 S. aureus D137 100   >100  1.6                                            Sa-10                                                                               S. aureus A20239                                                                              25    100   25                                             Ec-1 E. coli NIHJ   12.5  50    0.8                                            Ec-2 E. coli PO 1495                                                                               25    50    0.4                                            Ec-5 E. Coli ML 1630                                                                               12.5  50    100                                            Ec-9 E. coli NR 79/W677                                                                            25    100   25                                             Ec-10                                                                               E. coli JR 35/C600                                                                            6.3   12.5  12.5                                           Ec-49                                                                               E. coli A20107 12.5  50    25                                             Ec-53                                                                               E. coli JR 66/W677                                                                            6.3   25    25                                             Ec-55                                                                               E. coli R 5    25    100   6.3                                            Ec-62                                                                               E. coli A20895 12.5  50    0.8                                            Ec-72                                                                               E. coli A20732 12.5  25    12.5                                           El-2 Ent. cloacae A20364                                                                           25    50    100                                            El-12                                                                               Ent. cloacae A21006                                                                           25    100   50                                             Pv-1 Pr. vulgaris A9436                                                                            12.5  50    0.2                                            Pg-2 Pr. morganii A20031                                                                           25    50    0.8                                            Pm-1 Pr. mirabilis A9554                                                                           12.5  25    0.4                                            Ps-2 Prov. stuartii A20894                                                                         >100  >100  0.8                                            Kp-1 K. pneumoniae D11                                                                             3.1   12.5  0.2                                            Kp-8 K. pneumoniae Type 22-3038                                                                    25    100   100                                            Sm-1 Ser. marcescens A20019                                                                        >100  >100  0.8                                            Sm-16                                                                               Ser. marcescens A21247                                                                        100   >100  >100                                           Pa-3 Ps. aeruginosa A9930                                                                          12.5  25    6.3                                            Pa-12                                                                               Ps. aeruginosa A20653                                                                         25    100   >100                                           Pa-16                                                                               Ps. aeruginosa # 130                                                                          25    100   25                                             Pa-21                                                                               Ps. aeroginosa A20601                                                                         25    50    12.5                                           Pa-24                                                                               Ps. aeruginosa A20896                                                                         25    100   >100                                           Pa-27                                                                               Ps. aeruginosa GN 315                                                                         25    50    100                                            Px-10                                                                               Pseudomonas sp. A20621                                                                        >100  >100  12.5                                           __________________________________________________________________________

                  Table 7                                                          ______________________________________                                         Antibacterial Spectra Of Bu-2183 A and A.sub.2                                                    MIC (mcg/ml.)                                               Code # Test Organism     Bu-2183 A Bu-2183 A.sub.2                             ______________________________________                                         Sa-2   S. aureus Smith   25        25                                          Sa-3   S. aureus D193    25        50                                          Sa-4   S. aureus D133    50        100                                         Sa-9   S. aureus D137    50        100                                         Sa-10  S. aureus A20239  50        100                                         Ec-1   E. coli NIHJ      25        100                                         Ec-2   E. coli P01495    25        >100                                        Ec-5   E. coli ML1630    25        50                                          Ec-9   E. coli NR79/W677 12.5      25                                          Ec-10  E. coli JR35/C600 6.3       6.3                                         Ec-49  E. coli A20107    25        50                                          Ec-53  E. coli JR66/W677 25        25                                          Ec-55  E. coli R5        6.3       25                                          Ec-62  E. coli A20895    25        50                                          Ec-72  E. coli A20732    12.5      25                                          El-2   Ent. cloacae A20364                                                                              25        100                                         El-12  Ent. cloacae A21006                                                                              25        100                                         Pv-1   Pr. vulgaris A9436                                                                               25        100                                         Pg-2   Pr. morganii A20031                                                                              25        50                                          Pm-1   Pr. mirabilis A9554                                                                              25        50                                          Ps-2   Prov. stuartii A20894                                                                            >100      >100                                        Kp-1   K. pneumoniae D11 6.3       12.5                                        Kp-8   K. pneumoniae Type 22-3028                                                                       25        100                                         Sm-1   Ser. marcescens A20019                                                                           >100      >100                                        Sm-16  Ser. marcescens A21247                                                                           >100      >100                                        Pa-3   Ps. aeruginosa A9930                                                                             12.5      50                                          Pa-12  Ps. aeruginosa A20653                                                                            50        >100                                        Pa-16  Ps. aeruginosa # 130                                                                             25        100                                         Pa-21  Ps. aeruginosa A20601                                                                            50        >100                                        Pa-24  Ps. aeruginosa A20896                                                                            50        >100                                        Pa-27  Ps. aeruginosa GN315                                                                             25        100                                         Px-10  Pseudomonas sp. A20621                                                                           >100      >100                                        ______________________________________                                    

                                      Table 8                                      __________________________________________________________________________     Effect Of Media pH On MIC Of Bu-2183 A                                         Code No.                                                                            Strain      pH 6 pH 7 pH 8 pH 9                                           __________________________________________________________________________     Ec-1 E. coli NIHJ                                                                               >50  50   25   12.5                                           Kp-1 K. pneumoniae D 11                                                                         12.5 12.5 12.5 3.1                                            Pa-1 Ps. aeruginosa D 15                                                                        >50  50   25   12.5                                           Sa-10                                                                               S. aureus Smith                                                                            >50  50   50   50                                             Bs-1 B. subtilis PCI 219                                                                        50   6.3  6.3  6.3                                            __________________________________________________________________________

                                      Table 9                                      __________________________________________________________________________     Effect Of Media On Activity Of Bu-2183 A And B                                                  Bu-2183 A     Bu-2183 B                                       Code No.                                                                            Strain      NA* HIA MHA   NA  HIA   MHA                                   __________________________________________________________________________     Ec-1 E. coli NIHJ                                                                               12.5                                                                               50  100   50  >100  >100                                  Kp-1 K. pneumoniae D11                                                                          3.1 12.5                                                                               25    12.5                                                                               50    50                                    El-2 Ent. cloacae A20364                                                                        25  50  100   50  >100  >100                                  Pv-1 Ps. vulgaris A9436                                                                         12.5                                                                               50  100   50  >100  >100                                  Pm-1 Ps. mirabilis A9554                                                                        12.5                                                                               50  50    25  >100  100                                   Pa-3 Ps. aeruginosa A9930                                                                       12.5                                                                               25  50    25  100   >100                                  Sa-2 S. aureus Smith                                                                            12.5                                                                               50  50    50  100   >100                                  Sa-10                                                                               S. aureus A20239                                                                           25  100 >100  100 >100  >100                                  __________________________________________________________________________      *NA : Nutrient agar                                                            HIA : Heart infusion agar                                                      MHA : Mueller-Hinton agar                                                

                  Table 10                                                         ______________________________________                                         In Vivo Activity Of Bu-2183 A And B                                                         PD.sub.50 In Mg./Kg. (single dose)                                Infective Organism                                                                            Bu-2183 A   Bu-2183 B                                           ______________________________________                                         S. aureus Smith                                                                               42          100                                                 E. coli NIHJ   92          135                                                 Ps. aeruginosa A9930                                                                          230         540                                                              PD.sub.50 In Mg/Kg. (double doses)                                Infective Organism                                                                            Bu-2183 A                                                       ______________________________________                                         S. aureus Smith                                                                               36 × 2                                                    E. coli NIHJ   45 × 2                                                    Ps. aeruginosa A9930                                                                          80 × 2                                                    ______________________________________                                    

The following examples are offered only for the purposes of illustrating the present invention and are not intended to limit same in any respect. Amberlite IRC-50 and CG-50 mentioned in the disclosure above and in the examples which follow are the trade names for weakly acidic cationic exchange resins of a carboxylic-polymethacrylic type.

EXAMPLE 1 (Fermentation In Tank)

Agar slant culture of Pseudomonas sp. strain D946-B83 was used to inoculate 100 ml. of seed medium No. 83B (3% glucose, 2% fish meal, 0.5% soybean meal, 0.2% peptone and 0.6% CaCO₃) in 500 ml. Erlenmeyer flasks. The flasks were incubated at 28° C. for 3 days on a rotary shaker (250 rpm) and 1 liter of the seed culture was used to inoculate 300 liters of fermentation medium No. 100F (2% glycerin, 1% Pharmamedia, 2% fish meal, 2% linseed meal, 0.3% (NH₄)₂ SO₄, 0.6% CaCO₃). The tank was operated at 30° C. with stirring at 140 rpm and an aeration rate of 200 liters/minute. The broth potency was determined by the paper disc-agar plate method using B. subtilis PCI 219 as assay organism and Bu-2183 A as assay standard. The following results were obtained:

    ______________________________________                                         Time (hrs.)                                                                               pH of Broth   Potency (mcg./ml.)                                    ______________________________________                                         0          6.7           0                                                     20         7.5           200                                                   30         7.8           400                                                   40         7.9           1,600                                                 50         7.9           1,650                                                 60         8.1           1,700                                                 64         8.1           1,800                                                 ______________________________________                                    

EXAMPLE 2 (Extraction)

The harvested broth was filtered with filter aid at pH 2. The filtrate (19 liters) which contained about 30 grams potency of Bu-2183 A was adjusted to pH 7 and stirred with 3 liters of Amberlite IRC-50 (NH₄ ⁺ form). The resin was separated, washed with 10 liters of water and 5 liters of N/50 NH₄ OH successively, and then stirred with two 4 liter-portions of N/2 NH₄ OH to elute the bioactivity. The active eluates were combined, concentrated in vacuo and then lyophilized to afford 18.6 g. of white soli (about 700 mcg./mg.). This solid was dissolved in water and applied to a column of Amberlite CG-50 (NH₄ ⁺ form, 400 ml.). The column was washed with 2.2 liters of water and 3 liters of N/40 NH₄ OH successively, and then developed with N/20 NH₄ OH. The eluates were collected fractionally and examined by bioassay on B. subtilis plate and also by TLC (system S-117, ninhydrin). Appropriate fractions were combined, concentrated in vacuo and lyophilized to give the following solids.

    ______________________________________                                                               Bu-2183 Components                                       N/20 NH.sub.4 OH                                                                          Solid Wt.  (crude)                                                  ______________________________________                                         0 - 1.3 liters                                                                            --         no activity                                                - 2.5 liters                                                                            2.7 g.     A                                                          - 4.4 liters                                                                            7.8 g.     A + B (minor)                                              - 5.2 liters                                                                            3.3 g.     B                                                        ______________________________________                                    

EXAMPLE 3 (Preparation of Bu-2183 A)

The crude sample of Bu-2183 A (2.7 g.) obtained in Example 2 was dissolved in water and applied to a column of Amberlite CG-50 (NH₄ ⁺ , 80 ml.). The column was eluted with N/20 NH₄ OH and each 15 ml. portion of the eluate was collected by a fraction collector. Fractions were examined by TLC-ninhydrin and also by bioassay, and appropriate fractions were combined, concentrated in vacuo and lyophilized to give the following solids.

    ______________________________________                                         Fraction No.                                                                              Solid Wt.  TLC                                                      ______________________________________                                         28 - 53      801 mg.  A + impurity                                             54 - 72    1,597 mg.  A                                                        73  - 95     189 mg.  A + B (minor)                                            ______________________________________                                    

The pure preparation of Bu-2183 A was analyzed for C₁₅ H₃₁ N₃ O₉.1/2 H₂ CO₃ :

Anal. Calc'd: C, 43.45; H, 7.53; N, 9.81. Found: C, 43.22; H, 7.52; N, 9.49.

Its IR and NMR spectra are shown in FIGS. 1 and 2, respectively. A summary of the NMR data is given below:

    ______________________________________                                         Chemical Shift                                                                            Coupling Constant                                                                               Relative                                           (δ, ppm)                                                                            (J, Hz)          Intensity                                          ______________________________________                                            1.12 t  7.5              3H                                                    2.29 q  7.5              2H                                                 3.1-3.35 m                  2H                                                 3.5-4.3  m                  12H                                                   5.17 d  3.0              1H                                                 ______________________________________                                          s = singlet;                                                                   d = doublet;                                                                   t = triplet;                                                                   q = quartet;                                                                   m = multiplet                                                            

EXAMPLE 4 (Preparation Of Bu-2183 B)

The crude sample of Bu-2183 B (3.3 g.) obtained in Example 2 was dissolved in water and applied to a column of Amberlite CG-50 (NH₄ ⁺, 130 ml.). The column was eluted with N/20 NH₄ OH and each 15 ml. portion of the eluate was collected by a fraction collector. Fractions were examined by TLC-ninhydrin and also by bioassay, and appropriate fractions were combined, concentrated in vacuo and lyophilized to give the following solids.

    ______________________________________                                         Fraction No.                                                                              Solid Wt.  TLC                                                      ______________________________________                                          1 - 59      86 mg.   B + impurity                                              60 - 151  2,792 mg.  B                                                        152 - 160    356 mg.  B + impurity (minor)                                     ______________________________________                                    

The pure preparation of Bu-2183 B was analyzed for C₁₄ H₂₉ N₃ O₉.1/2 H₂ CO₃ :

Anal. Calc'd.: C, 42.02; H, 7.30; N, 10.14. Found: C, 41.92; H, 7.43; N, 9.93.

Its IR and NMR spectra are shown in FIGS. 5 and 6, respectively. A summary of the NMR data is given below:

    ______________________________________                                         Chemical Shift                                                                            Coupling Constant                                                                               Relative                                           (σ, ppm)                                                                            (J, Hz)          Intensity                                          ______________________________________                                            2.02 s                   3H                                                 3.1-3.2 m                   2H                                                 3.6-4.3 m                   12H                                                   5.17 d  3.0              1H                                                 ______________________________________                                          s = singlet;                                                                   d = doublet;                                                                   m = multiplet                                                            

EXAMPLE 5 (Preparation of Bu-2183 C and Bu-2183 D)

The column used in Example 2 was further developed with 1.4 liters of N/20 NH₄ OH, with which no more bioactive material was eluted. The column was then developed with N/10 NH₄ OH and the eluates were examined by TLC sprayed with ninhydrin reagent. Appropriate fractions were combined, concentrated in vacuo and lyophilized to give the following solids.

    ______________________________________                                         N/10 NH.sub.4 OH                                                                          Solid Wt.     Indentification                                       ______________________________________                                            0 -   300 ml.                                                                          --                                                                    301 - 1,200 ml.                                                                         1,638 mg.     Bu-2183 C                                             1,201 - 1,900 ml.                                                                         --                                                                  1,901 - 2,400 ml.                                                                           526 mg.     Bu-2183 D                                             ______________________________________                                    

EXAMPLE 6 (Preparation of Bu-2183 A₂)

During the purification process of component A described in Example 3, a new active component was isolated from forerun fractions and designated as component Bu-2183 A₂. It was differentiated from component A by the TLC systems S-117 and S-122 as shown below:

    ______________________________________                                                  Bu-2183 A   Bu-2183 A.sub.2                                           ______________________________________                                         S-117      Rf = 0.49     Rf = 0.57                                             S-122      Rf = 0.39     Rf = 0.48                                             ______________________________________                                    

The Ir and NMR spectra of component Bu-2183 A₂ are shown in FIGS. 3 and 4. A summary of the NMR data is given below:

    ______________________________________                                         Chemical Shift                                                                            Coupling Constant                                                                               Relative                                           (σ, ppm)                                                                            (J, Hz)          Intensity                                          ______________________________________                                            0.92 t  7.5              3H                                                    1.63 sixtet                                                                            7.5              2H                                                    2.30 t  7.5              2H                                                 3.1-3.5  m                  2H                                                 3.6-4.4  m                  12H                                                   5.27 d  3.0              1H                                                 ______________________________________                                          d = doublet;                                                                   t = triplet;                                                                   m = multiplet                                                             

We claim:
 1. A process for producing the antibiotic complex Bu-2183 which comprises cultivating Pseudomonas sp. strain D946-B83, A.T.C.C. 31086, in an aqueous nutrient medium containing assimilable sources of nitrogen and carbon under submerged aerobic conditions until a substantial amount of Bu-2183 is produced by said organism in said culture medium.
 2. The process of claim 1 which includes the further step of recovering the Bu-2183 complex from the culture medium.
 3. The process of claim 1 which includes the separation of the Bu-2183 complex into the individual components Bu-2183A, Bu-2183B, Bu-2183A₂ and Bu-2183D by the steps of(a) separating the Bu-2183 complex from the mycelium; (b) adsorbing the complex on a cationic ion-exchange resin; (c) fractionally eluting the Bu-2183 components from the adsorbent; and (d) recovering the fractions of the desired components Bu-2183A, B, A₂ and D. 